Tool holder



B. T. BROWAND.

Tom HOLDER. APPLI CATION FILED FEB. l4, 92|.

Patented Oct. 31, 11922.,

i To all whom it may concern;

1 WJAM T- B W ND, 6F bnnviiiliiizrn, o io. i

jroornornniik v n ncation filed February l; 1921: steam. 444,756.

1 Be" it known that BENJAMIN BRoW- nnoyacitlzen ofthe United States,-residing i at Cleveland, in thecounty of Cuyahoga and State of ()hio ha've invented'a certain new and useful Improvement" in Tool Holders ofiwhich the'following is a 11 11, clear, and

exact desc-riptionw a a NIP-his invention relates to a'tool holder "with special utility ftor milling machines; al-

though not necessarily confined to such nachines. Y

pWith certalnwmachlne tools the rotating 1 part or spindleis provided' with a taper a socket, and the toolwitha'taper shanlcwhich is tightly driven into "the? socket so" that the a same willbe heldin place'and driven or rotatedYduring the cutting or xniachining 01o 1 erationr With manykindsof tools the tight ofthe taper shank into the taper socket isfiampie-w hold) the tool in place,lout with e certain other tools," such as milling rnachines; i and. particularly whenvdriving asuri'acing in-1i andvendccutting tool,the ei1tting action has a 3 tendencyv to pulltthe an out of thefsocket. This often happens; frequently with serious results to theaworlr and tool breakage and destruction off-the tool generally resulting.

; 1 w This is-amatterofconsiderable consequence in view of the fact that the cutting: partof the tool is generally -for1ned oi" so-called highsspee d steel,which, particular1y at the present; time, is exceedinglyexpensive. It

I "1 sometimes happens also that theload on the 1 tool isso great as to twistor breakoff the flat tang at therear end of the tool; a i

j y lt-is one of theolojects oi. the present ins ventionuto provide a 1 holder of the taper in 11 n socket type with meansgfor positively ipre- 4o ventingduring theicutting operation the ace tang of part of the torsional stresses.

cidenta-l pulling of the tapershank fromthe sockets A further object is to provide ad v ditional means forresistingithe turning'of the tool in the taper socket and thus relieve 1} It is afurther airn of the invention to itC-j complish the alcove nentionedboloject with out requiring any; change or material change, in the construct on OfillWHlELGlllIlQ;

5 0 tool; and in. such a "way thatithe invention can flloe.readilyfapplied, if desired, to machine Y toolsvalready built.

Q The inventionihiayhe briefly-summarized t as consisting in certain.novel detailsgof (1011+ 1 V struct1on,and combinations and arrangei alslightl'y rednced scale; Fig. 3 'isa sectional 1 viewsuhstantially along the line 3-3ofFig;

1, looking in the direction indicated by the arrowyFigptfisj an'end view ofthe collet with thewtool removed; Fig. 5 is aperspec tive view ofone of the dogs utilized to assist in holding the tool in the collet; Fig. 6 is a fragmentary sectional View showing a slight modification in the way of preventing theudogs dropping: from the collet; 7

and 8 are side views of the inner end of the toolshownn-in Fig. 1 to-illustrate the Hat hottornnotcheswhich are adapted to be engaged hythe dogs when forced inWa-rdhy a tightenlngrlng; Fig. 9 1s a sinnlar view showing a tool with a continuous groove to receiver'the inner ends of the dogs instead of the separated flat bottom in Figs. 7 and 8. r r i a In the accompanying sheet of drawings, 10=represents aitapered collet which is custornarily' employed to receive a tool such as notches shown a milling tool, and: is adapted to be inserted I in the rdtating driving spindlelof a machine tool such as-a millingmachine. i

"Thiscollet :is provided with the usual tapered n body for insertion in the tapered "socket of the spindle andin this instance the, collet is provided just forward of the tapered body with a pair of oppositely disposed ilugs ill whieh are adapted to be inserted in rectangular notches formed in the frontienfd ofthe spindle and forward of these lugs the collet has an annularthreaded portion=12adaptedto receive a locking ring; 13, the purpose oirwhich will be ex- The collet a tapered socket l l which is designed toreceivethe tapered spindle 15 of a cutting tool 16, the rear or inner end otkthe shank 15 havingthe usual tang 17 which is receivedinto the reduced end 14 of the {socket in, the collet; In the drawing ll have shown 1a so oalled surfacing and cnd cutting tool with spiral cutting edges. Vith a tool of this kind there exists the before mentioned tendency of the tool to pulled o ut o f QSbCket cutting operation, this being ordinarily res ste solely by the frictional engagement hetween the tapered shank of'the to'oY-aiid the tapered-wall or socket of the collet. Further; more, the turning of the tool in the collet is ordinarily resisted almost entirely by the tang of the tool. But when the load onthe be m s s ressive t sometimes happens that this tang is} twisted oil. To prevent the tool, such as the one herein illustrated,

being pulled out of the socket and to prevent the ang being ea -en byes sicliel ad g ea er than th ti e a .1 tain, I provide the present invention.

In the collet provide, two diagonally. disposed: Q e ngs mil a p g being disposed at an angle of 1 approximately 159 to the axis. of the? collet. The outernds of these openingsare inthe forward sides of the. lugs 111, 01. rather at the intersection of; the inner, faces-of these lugs with the annular part of the collet' forward of these lugs, the threaded portion adjacent these openings being preferably inilledfofi as shown at 18*. The inner ends of these openings 18'intersect' the inner tapered surface of the collet forming: the tapered socket 114.

In these diagonally disposed openings 18 tool holding, dogs or, plnngers 19;. arep rm 'vided, these-dogs being, in the fdrmfo f latejrally elongated hardened steel member's withinnertapered ends "195. ihe opposite faces of the dogs "are flat and parallel, and their longitudinal edges are rounded so as to conform in shape'to the cross sectional outline of the openings 18-.

Any suitable means may be provided for preventing. H 65? dogs dropping into the socket of""the collet when the tool is removed, and in 1, 3 and 5 the outer ends of the dogs are provided withli s19 which serve this purpose. In the mo i'fication shown in Fig; 6 the lugs 11* are provided with small's crews 20. which extend from the back. face of the lugs: 11 diagonally inward at right angles to the dogs and en gage in shallow elongated slots on therear sides of tli'e dogsf In order that these dogs may hold the tool against being pulledfronithe socket of the collet, the shank of the tool is" providedwith appropriately shaped dogfreceiving recess or recesses, and if v thefdogs are. to -havev the additi'dnal" function of relieving. the tang of part of; the twisting or torsional stresses the dog receiving means of the tool shank consists of a pair o f 'fl'at bottomed notches 9L1 oppositely disposed on opposite sides of the shank of'the tool, so; located that when the tool is'afull dis} tance in the socket of the collet the inner ends of the dogs will engage and may be forced up against the rear or inner portions of theseflat notches precisely as shown in Fig-" i Instead of providing the shank of the tool with fiat'notches 21 for the purpose stated, it may be provided with a continuous grades 22 substantially as shown in Fig. 9, in which event the inner ends of the dogs will bear against the rear face 22' of this groove.

Referring now again to the ring 13 forming a part of my improved construct on. it will he observed that the rear end. of the ring is tapered at an angle of 45, so that when the ring is screwed back towards the lugs 11 the tapered rear edge of the ring will engage the outer protruding ends of the dogs 19, and will force them inward with apressure exerted longitudinally of thedogs.

Before the tool is inserted in the collet the ring will be backed away somewhat so as to permit the tapered shank of the tool to be inserted in the usual fashion. Vhcn thev tool has been inserted the full distance. it is only necessary to screw back the ring 13 with a spanner wrench or other suitable tool, or by hand if desired, and the effect of this ring is to force the dogs inward and cause their inner ends to bear solidly against the rear tapered portions of the oppositely disposed notches 21, in the event the. notches are utilized, or against the rear tapered portion of the annular groove, in the event the groove of Fig. 9 is utilized. Therefore, these dogs will prevent entirely the accidental withdrawal of the tool from the socket, and when the tool is provided with the flat bottomed notches of Figs. 7 and 8, they additionally sustain part of the torsional loadtransmitted from the tool to the collet and thus relieve the tang of a portion of the stresses which it would otherwise be required to bear. Therefore, this tool can be used under maximum load without liability either of the tool coming out of the collet or of a tang being broken off.

When it is desired to remove the tool from the collet the ring 13 is loosened up so as to allow of suflicient freedom of movement of the dogs to permitthe tool being driven out by the usual drift pin or tool.

In the event it is desired to tightly clamp the ring 13 in place, I may pr'ovi e a set screw 23 s'ucl' 'as'shown in ig. 1, in which event I prefer to provide at the bottom of the tapped opening which receives the screw, a plug 24; whose inner surface is threaded in conformity with the threading on the inner surface of the ring. 'When the set screw 23 and the plug 24 are provided, by tightening down on the set screw, the ring 13 can be locked in place. However, Idonot regard the use ofthe set screw '23 and plug2 l as employed if desired.

It will be seenftherefore, that I have pr0- vided an improvement 01. considerable merit in machine tools, particularly milling tools, and that the objects stated at the beginning oi? the specification are attained very efliectively with the construction herein illustrated.

Having described my invention, I claim: 1. A rotatable toolholder having a taper socket, a tool having. a taper shank adapted to be driven into the socket and provided with a recess having a shoulder, the holder having a diagonally disposed endwise mov able dog or plunger together with means for forcing the dog or plunger inwardly so i as to cause its inner end to engage the shoulder.

2. A toolholder having a taper socket and a tool having ataper shank fitted into the socketand provided between its ends with one or more shouldered seats, andthe holder having at theend in which the shank is in serted, a threaded portion, a nut engaging said threaded portion, and a plurality of movable plungers extending diagonally through the holder and so disposed that they will'be moved inward by said nut so that each will engage the shoulder of the tool when the latter is a pair of oppositely disposed recesses having shoulders, and means for preventing the tool being accidentally withdrawn from the socket and for carrying part of the torsional essential to the invention,though it can be stressestransniitted from the tool to the holder, comprising a pair of diagonally disposed. dogs or plungers mounted in the holder and adapted at their inner ends to engage said shoulders of the recesses of thetool, and means for forc ng sald dogs or plungers 1n wardly against said shoulders.

4:. A rotatable tool holder having a taper socket in combination with a tool having a taper shank adapted to be driven into the taper socket and providedwith recesses having flat faces and shoulders, said holder having near its end a threaded portion, a nut engaglng said threaded portion, dlago nally disposed plungers or dogs extending diagonally inward to the taper socket of the holder, said plungers being so disposed that when engaged and forced inward by the nut their inner ends will engage the fiat faces and shoulders of the recesses of the shank of the tool. v

5. A rotatable tool holderhaving a taper socket, a tool having a'taper shank adapted to be driven into the socket and provided with a pair of inclined shoulders, the holder able in, lines substantially at right angles i being provided with a pair of plungers niovto said inclinedshoulders, and the holder having near its outer end anut whose inner end is tapered at substantially right angles to said plungers and adapted to engage the outer ends oi? theplungers to move them inward and force them solidly against said shoulders. r

In tGS tlIIIOIIYWVhGIGOf, I hereunto ailix my s1 gnature.

BENJAMIN r. BROWAND. 

